1. Field of the Invention
This invention relates in general to inductors for use in integrated circuits, and relates more particularly to integrated circuit inductors having magnetic cores.
2. Description of the Related Art
Inductors are used in a wide range of signal processing systems and circuits. For example, inductors are used in communication systems, radar systems, television systems, high pass filters, tank circuits, and butterworth filters.
As electronic signal processing systems have become more highly integrated and miniaturized, system designers have sought to eliminate the use of relatively large auxiliary components, such as inductors. One approach to eliminating the use of actual inductors in signal processing systems is to simulate inductors using active circuits, which can be easily miniaturized. Unfortunately, simulated inductor circuits tend to exhibit large parasitic effects and often generate more noise than circuits constructed using actual inductors.
When unable to eliminate inductors in their designs, designers have sought ways to reduce the size of the inductors that are used. For example, inductors are miniaturized for use in compact communication systems, such as cellular phones and modems. These miniaturized inductors typically comprise two-dimensional spiral inductors that are fabricated on the same substrates as the integrated circuits to which they are coupled. Although these two-dimensional spiral inductors can be fabricated using conventional integrated circuit manufacturing techniques, they typically take up a disproportionately large share of the available surface area on an integrated circuit substrate.
For these and other reasons, there is a need for the present invention.
An inductor comprises a substrate, a magnetic core formed in a region of the substrate, and a conductive coil interwoven with the substrate and surrounding the magnetic core.
In one embodiment, an inductor comprises a substrate, a magnetic core formed on the substrate, and a three-dimensional conductive coil. The conductive coil comprises a plurality of conductive posts interconnected by a plurality of conductive segments such that the conductive coil surrounds the magnetic core.
In one embodiment, an inductor comprises a substrate comprising a semiconductor having a crystalline structure, a magnetic core formed on the substrate, a plurality of paths extending through the substrate, and a conductive coil woven through the plurality of paths and surrounding the magnetic core. The conductive coil is at least partially diffused into the crystalline structure.
In one embodiment, a device comprises a substrate and an inductive structure having an inductance of at least 1 nanohenry (nH). The inductive structure includes a magnetic core and is at least partially embedded in the substrate.
In one embodiment, an inductor comprises a substrate, a magnetic core formed on the substrate, a pair of substantially parallel rows of conductive posts providing a plurality of conductive paths through the substrate, and a plurality of conductive segments interconnecting the pair of substantially parallel rows of conductive columns to form a conductive coil surrounding the magnetic core.
In one embodiment, an inductor comprises a perforated substrate, a magnetic core formed on the perforated substrate, and a conductive material interwoven with the perforated substrate and surrounding the magnetic core. The conductive material is at least partially diffused into the perforated substrate.
In one embodiment, an inductor comprises a substrate having a top surface and a bottom surface, a plurality of holes extending through the substrate, wherein the plurality of holes interconnect the top surface and the bottom surface. The inductor further comprises a plurality of conductive posts formed in the plurality of holes, a plurality of conductive segments formed on the top surface and on the bottom surface that interconnect the conductive posts such that a continuous conductive coil is formed; and a magnetic core occupying substantially the entire volume enclosed by the conductive coil.
In one embodiment, an inductor comprises a multilayer substrate, a magnetic core formed on the multilayer substrate, and a coil interwoven with the multilayer substrate and surrounding the magnetic core.
In one embodiment, a device comprises an integrated circuit formed on a substrate, a magnetic core formed on the substrate, and an inductor interwoven with the substrate and surrounding the magnetic core, wherein the inductor is operably coupled to the integrated circuit.
In one embodiment, a memory system comprises a substrate having a plurality of memory circuits, a magnetic core formed in a region of the substrate, and a conductive coil interwoven with the substrate and surrounding the magnetic core.
In one embodiment, a computer system comprises a processor and an inductor comprising a substrate, a magnetic core formed on the substrate, and a conductive coil interwoven with the substrate and surrounding the magnetic core. The computer system further comprises an electronic device coupled to the inductor and to the processor.
In one embodiment, a method of fabricating an inductor embedded in a substrate comprises the steps of forming a magnetic core in the substrate and fabricating a three-dimensional conductive coil around the magnetic core.
In one embodiment, a method of fabricating an inductor embedded in a substrate comprises the steps of forming a plurality of paths extending through the substrate, forming a magnetic core in the substrate, depositing a conductive material in the paths to form a plurality of conductive posts, and fabricating a plurality of conductive segments that interconnect the conductive posts to form a conductive coil.